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Meade ETX 90
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Specifications
Optical design: Maksutov-Cassegrain
Clear aperture: 90mm (3.5")
Focal length: 1250mm (48.6")
Focal ratio (photographic speed): f/13.8
Near focus: 3.5m (11.5')
Resolving power: 1.3 arc secs
Super Multi-coatings: standard
Limiting visual stellar magnitude: 11.7
Maximum practical visual power: 325x
Optical tube dimensions: D=10.4cm x L=27.9cm (4.1" x 11")
Secondary mirror obstruction: 27.9mm (1.1"); 9.6%
Telescope mounting: fork type; double tine
RA drive motor: 4.5-volts DC
Hemispheres of operation: north and south; switchable
Slow-motion controls: manual; R.A. and Dec
Bearings:R.A. and Dec: Nylon
Materials:
Tube body: aluminum
Mounting: high-impact ABS, steel reinforced
Primary mirror: Pyrex glass
Correcting lens: BK7 optical glass, Grade-A
Telescope dimensions: 38cm x 18cm x 22 cm (15" x 7" x 9")
Telescope (incl. tripod) net weight: 4.2kg (9.2 lbs)
Telescope shipping weight: 5.6kg (12.4 lbs)
Source: ETX User Manual
Comments
ETX is a telescope for the beginner, or a second telescope for a more
serious astronomer that is looking for portability. It is relatively cheap and a bargain
compared with Questar, which is better quality though. It is very good to look at the
planets, Moon and the Sun, this being the reason I bought the ETX telescope. Is not very
good for deep sky objects because of its small aperture (90mm).
The Binocular & Telescope Shop is a good place to buy a telescope or any other accesory for a telescope.
Gabriel Ditu
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Designed by Gabriel Ditu ©Copyright 2008
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